I'll grant you that once we have found a single other planet with life. Until then we're doing statistics on a single data point and no, the number of planets and galaxies etc are not sufficient to statistically determine the prevalence of life because as yet none of them are confirmed to have life. This is wishful thinking and statistical truthiness.
Is the single one in a million dimensional one-hot vector special? Why?
If only intelligent life can have this conversation then it will always be "but why us?!?!" well, it was random. Just the other random values don't get to ask the question...
"It was random" in my opinion explains little. If it was sentient, maybe the dice would say "why did I land showing my '6' face? Why me?" and the answer would be many other dice landed showing their '6' faces. Random, but given enough dice rolling you'll get another '6'.
The universe is finite but it's mind-boggingly large. I think Earth is special because a- I was born there, enough said, and b- it has just the right conditions and luck for life to exist. But I don't think it's so special that it's the only planet in the whole mind-boggingly large universe to be this way. There must be other planets/dice rolling out there.
Until we find another such planet we cannot know for certain, but in my opinion it seems unlikely that these conditions don't exist anywhere else but on Earth. Why? Well, because the universe is so large -- the dice pool is very, very large.
In my case, my gut feeling, but is it so unlikely?
As mentioned in "Cosmos: Possible Worlds", planets may go through a "habitable zone", which is the window in which they are just the right distance from just the right star, and they have the right elements in their surface or whatnot. And then just the right random events have to happen and there's the spark of life. And then a gazillion extinction events must be averted, at times when the Tree of Life (to use the metaphor from Cosmos) is at its most fragile, when all of life could be cut down before its prime.
It sounds unlikely for any single planet, any single star system, any single galaxy, etc. But on the grand scale of the universe, it cannot be that nowhere else but here on Earth did this happen.
I don't know if this is statistics. It surely is gut feeling. But I think it's the right kind of gut feeling...
It's possible that life emerging is so unlikely that it has never happened before anywhere even if it could happen again. We do not have the data to establish how likely and in fact we don't even have enough data to fill in all the gaps of how life on earth emerged in the first place. Our gut feelings are likely heavily influenced by science fiction or other priors and can't be trusted for knowledge but we are as a species very good at deluding ourselves into thinking we know things that we don't.
What's difficult to comprehend is the immense vastness of the universe. It seems unlikely that nowhere else did the preconditions for life arise, and in fact, it seems likely that they must have arisen in multiple places. Immensely many places, in fact. Considered like that, it's more unlikely that life didn't appear anywhere else but in this Pale Blue Dot.
We look at our planet, and all that had to happen for those first lifeforms to come into existence, and it seems so unlikely... but not impossible. And we're playing with a lot of dice here! Very hard not to roll a few sixes with a bag of dice so large.
> What's difficult to comprehend is the immense vastness of the universe.
We know a whole lot about ways life changes once it's there but we haven't observed life emerging from non-life and our hypotheses for how life emerged on earth has more holes than swiss cheese and it doesn't have to be magic in order to be exceedingly improbable. And magnitudes work in both ways, if it is sufficiently improbable for life to emerge, let's say 1 chance in 1E100 against then even if you had dice rolls in proportion to all the subatomic particles in the universe (~1E80) multiplied by the number of seconds since the big bang (~4E17) then it would still be about 3 orders of magnitude against the likelihood of life emerging even once. In this scenario if the probability was 4E97 then we'd expect for life to have emerged once. Until we have the data to infer what the probability actually is we can't determine which scenario is the case.
> but we haven't observed life emerging from non-life
But our laboratory is very, very small, so that proves little.
And we know life emerged at least once, and it doesn't seem particularly improbable. That's what I mean by "not magic"; not that we understand every little step, but we have some idea.
I don't think it's scifi to believe it's unlikely only Earth has sparked life. The one thing that is unlikely is that we will ever witness life anywhere else, but that's a different problem.
For the difficulty of evolution of life, we have a total N of 1-5 of life-could-have-evolved, depending on how optimistic or pessimistic you want to be about life's chances (could life have evolved on Venus? Mars? Titan? Europa? any other moons I'm forgetting about).
At this point, the statistics says more about your priors than they do about actual data, since there's not enough data to actually do any statistics on.